Quality control, or QC for short, is a process by which entities review the quality of all factors involved in production. ISO 9000 defines quality control as "A part of quality management focused on fulfilling quality requirements".[1]

Controls include product inspection, where every product is examined visually, and often using a stereo microscope for fine detail before the product is sold into the external market. Inspectors will be provided with lists and descriptions of unacceptable product defects such as cracks or surface blemishes for example.

The quality of the outputs is at risk if any of these three aspects is deficient in any way.

Quality control emphasizes testing of products to uncover defects and reporting to management who make the decision to allow or deny product release, whereas quality assurance attempts to improve and stabilize production (and associated processes) to avoid, or at least minimize, issues which led to the defect(s) in the first place.[citation needed] For contract work, particularly work awarded by government agencies, quality control issues are among the top reasons for not renewing a contract.[4]

Popularized by Armand V. Feigenbaum in a Harvard Business Review article[6] and book of the same name.[7] Stresses involvement of departments in addition to production (e.g., accounting, design, finance, human resources, marketing, purchasing, sales).

In project management, quality control requires the project manager and/or the project team to inspect the accomplished work to ensure its alignment with the project scope.[10] In practice, projects typically have a dedicated quality control team which focuses on this area.[citation needed]

^Evans, James R.; Lindsay, William M. (1999), The Management and Control of Quality (4 ed.), Cincinnati, Ohio: South-Western College Publications, p. 118, ISBN9780538882422, OCLC38475486, The term total quality management, or TQM, has been commonly used to denote the system of managing for total quality. (The term TQM was actually developed within the Department of Defense. It has since been renamed Total Quality Leadership, since leadership outranks management in military thought.)